void main() {
  //1.字符串
  var str1 = "aaa";
  var str2 = "bbb";
  String str3 = "ccc";
  //dart的模板字符串
  String str4 = '''
    1
    2
    3
    4
    5
  ''';
  print(str1);
  print(str2);
  print(str3);
  print(str4);

  //2.字符串拼接
  String str5 = "Hello";
  String str6 = "Dart";
  print(str5 + " " + str6); //Hello Dart
  //模板占位
  print("$str5---$str6"); //Hello---Dart
}
